I was reading the thread and and going to clarify how andwhy vtec-e works. Basically it does not have the performance Vtec that activates after 5k. But under 3k half the intake valves don't open at all and one stays barely open. Not for the "swirl affect" but for a leaner fuel/ air ratio. Along with the harness they are a few differences with the swap. Not sure if your header has a cat. conv but that very local o2 sensor enables it to check its unburned fuel quicker than the catback cat. conv. Other than that its mostly up to the really long geared hx transmission that lets it get the higher mpgs. Personally i'm going to switch out my hx tranny for an ex as a comfort upgrade for city driving. You really have to drive it with a light foot to get the lean burn to kick in at lower mph. but after first gear you could comfortably use 2nd up to 55 mph(street racing?) and 3rd to 100mph. You could get a new head(roller rockers!), harness, tranny,ecu, and intake manifold(slightly smaller/ higher pressure), for a complete frankenstein swap. But frankly thats alot more money and work for a 45-50 mpg car. think of the long run. you will find 100k+ mile used parts and invest well over 1500 bucks for that swap and run it for another 100k if everything was done perfectly. while you can run your current engine into the ground and just get a whole new(60kish) ek ex/dx/vx(manual hopefully) swap. I get a steady 38+ rural country and city driving. with my 165k hx without aero mods on stock pos tranny with 2 12's in the back,(not as eco as many of you
/ my advice is run urs into 300k while saving for a used hx. they are out there, they just take an extra month or 2 to grab. If you ever find a young HX buy it up and mod the **** outa it. i'm willing to bet they can hit 90+mpg. surprised they haven't yet